Bio-efficacy of tembotrione 42% SC w/v (34.4% SC w/w), a new herbicide for post-emergence control of mixed weed flora in maize was evaluated during rainy seasons 2009 to 2015 at CCS Haryana Agricultural University, Regional Research Station, Karnal and also through multi-location adaptive/farmer-participatory trials. Post-emergence application of tembotrione 120 g/ha along with surfactant (1000 ml/ha) at 2-4 leaf stage was found most effective against grassy and non-grassy weeds as compared to other herbicidal treatments either applied as pre- or post-emergence (including its lower doses, atrazine and 2,4-D) resulting into the highest productivity (3.77-4.44 t/ha) and profitability (B-C ratio 1.75-1.98) of maize in on-station experiment during 2009-2010. On an average, grain yield of maize under tembotrione 120 g/ha along with surfactant (4.04-5.00 t/ha) was also better than the atrazine 500-750 g/ha (3.59-4.43 t/ha) and untreated check (2.86-3.33 t/ha) at multi-location trials during 2013-2015. There was no residual toxicity of tembotrione on succeeding wheat. Residues of tembotrione at 120 g/ha + S 1000 ml/ha and 240 g/ha + S 1000 ml/ha in raw cobs, grains and straw of maize and soil were also below detectable level during 2015.